470 HOMEE WHEELON 



absent about' the anus and diminished about the pubes and axillae. Hair 

 on the face may be well developed in old age, but this is also true of old 

 women. The pelvis also is infantile, but not feminine in type. 



Studies on the effects of castration, gonad transplantation, the adminis- 

 tration of orchitic extracts and a consideration of pathological conditions 

 of the testes constitute a large body of information which intimately con- 

 nects sexual phenomena with the internal secretion of the testes. This 

 gonadal hormone has the power to influence the metabolism of many 

 somatic structures. The results as a whole demonstrate that the extent of 

 sexual modification in the experimental animal, in general, is in propor- 

 tion to the immaturity of the operated or treated animal. In other words, 

 the earlier the internal secretion of the gonad is supplied or withdrawn, the 

 more profound is the sexual modification of the individual. Indeed, 

 pseudohermaphroditism may logically be explained in many cases because 

 of an imbalanced equilibrium between the gonadal influences in the mother 

 and child in utero (Broek). 



In conclusion it may be said that the internal secretion of the testes 

 acts as a differentiating factor sufficiently strong to cause deviation from 

 the common path of somatic growth and to stimulate the development of^ 

 characters of sex. The withdrawal of this factor permits alterations lo 

 occur in the somatoplasm ivhich are proportionate to the degree of estab- 

 lishment and dependence of such characters upon the gonadal influence. 



